Sample analysis system with fiber optics and related method

ABSTRACT

A sample analysis system comprises a plurality of media containers, a plurality of sample test sites, a plurality of media sampling lines, a plurality of optical source lines, a plurality of optical return lines, and an optical input selection device. Each media sampling line is adapted for transferring a quantity of media from a corresponding one of the media containers to a corresponding one of the sample test sites. Each optical source line has an optical source line input end and an optical source line output end. Each optical source line output end communicates with a corresponding one of the sample test sites. Each optical return line has an optical return line input end and an optical return line output end. Each optical return line input end communicates with a corresponding one of the sample test sites. The optical input selection device is rotatable about a first axis, and comprises a first internal optical fiber having a first input end and a first output end. The first input end is disposed collinearly with the first axis. The first output end is disposed at a radially offset distance from the first axis and is alignable with a selected one of the optical source line input ends.

FIELD OF THE INVENTION

[0001] The present invention relates generally to the analysis ofsamples by optical-based techniques. More particularly, the presentinvention relates to the coupling and routing of selected input andoutput lines or channels through which optical signals are directed, andto the routing of optical signals to and from such lines or channels. Inparticular, the present invention relates to the design and use of adevice cooperating or integrated with a sample analysis system, whichdevice enables selection and coupling through coordinated mechanicalindexing movements and/or the use of optical fiber bundles whose endsare exposed to a detector. Such a device provides advantage in a widevariety of fields of application, particularly in applications involvingthe generation and transmission of analytical information. Specificfields of use include the preparation, sampling and analyzing of solublematerials as well as the testing of other fluids and solid materialsexhibiting optical characteristics.

BACKGROUND OF THE INVENTION

[0002] Optical transport techniques are often utilized to direct a beamor pulse of light from a light source to a test site and, subsequently,to carry analytical information generated or measured at the test siteto a suitable light receiving device. Analytical information transmittedby optical means can be chemical or biological in nature. For example,the analytical information can be used to identify a particular analyte,i.e., a component of interest, that is resident within the samplecontained at the test site and to determine the concentration of theanalyte. Examples of analytical signals include, among others, emission,absorption, scattering, refraction, and diffraction of electromagneticradiation over differing ranges of spectra. Many of these analyticalsignals are measured through spectroscopic techniques. Spectroscopygenerally involves irradiating a sample with some form ofelectromagnetic radiation (i.e., light), measuring an ensuingconsequence of the irradiation (e.g., absorption, emission, orscattering), and interpreting of the measured parameters to provide thedesired information. An example of an instrumental method ofspectroscopy entails the operation of a spectrophotometer, in which alight source in combination with the irradiated sample serves as theanalytical signal generator and the analytical signal is generated inthe form of an attenuated light beam. The attenuated signal is receivedby a suitable input transducer such as a photocell. The transducedsignal, such as electrical current, is then sent to a readout device.

[0003] As one example for implementing spectral analysis, aspectrophotometer uses ultraviolet (UV) and/or visible light, or inother cases infrared (IR) or near infrared (NIR) light, to scan thesample and calculate absorbance values. In one specific method involvingthe UV or UV-visible spectrophotometer, the UV sipper method, the sampleis transferred to a sample cell contained within the spectrophotometer,is scanned while residing in the sample cell, and preferably is thenreturned to the test vessel.

[0004] The concentration of a given analyte in a sample throughspectrochemical determination typically involves several steps. Thesesteps can include (1) acquiring an initial sample; (2) performing samplepreparation and/or treatment to produce the analytical sample; (3) usinga sample introduction system to present the analytical sample to thesample holding portion of a selected analytical instrument (e.g.,transferring the sample to the sample-holding portion of a UVspectrophotometer); (4) measuring an analytical signal (e.g., an opticalsignal) derived from the analytical sample; (5) establishing acalibration function through the use of standards and calculations; (6)interpreting the analytical signal based on sample and referencemeasurements; and (7) feeding the interpreted signal to a readout and/orrecording system.

[0005] Conventional equipment employed in carrying out the aboveprocesses are generally known in various forms. Measurement of theanalytical signal involves employing a suitable spectrochemical encodingsystem to encode the chemical information associated with the sample,such as concentration, in the form of an optical signal. Inspectrochemical systems, the encoding process entails passing a beam oflight through the sample under controlled conditions, in which case thedesired chemical information is encoded as the magnitude of opticalsignals at particular wavelengths. Measurement and encoding can occur inor at sample cells, cuvettes, tanks, pipes, solid sample holders, orflow cells of various designs.

[0006] In addition, a suitable optical information selector is typicallyused to sort out or discriminate the desired optical signal from theseveral potentially interfering signals produced by the encodingprocess. For instance, a wavelength selector can be used to discriminateon the basis of wavelength, or optical frequency. A radiation transduceror photodetector is then activated to convert the optical signal into acorresponding electrical signal suitable for processing by theelectronic circuitry normally integrated into the analytical equipment.A readout device provides human-readable numerical data, the values ofwhich are proportional to the processed electrical signals.

[0007] For spectrophotometers operating according to UV-visiblemolecular absorption methods, the quantity measured from a sample is themagnitude of the radiant power or flux supplied from a radiation sourcethat is absorbed by the analyte species of the sample. Ideally, a valuefor the absorbance A can be validly calculated from Beer's law:${A = {{{- \log}\quad T} = {{{- \log}\frac{Ρ}{Ρ_{0}}} = {abc}}}},$

[0008] where T is the transmittance, P₀ is the magnitude of the radiantpower incident on the sample, P is the magnitude of the diminished (orattenuated) radiant power transmitted from the sample, a is theabsorptivity, b is the pathlength of absorption, and c is theconcentration of the absorbing species.

[0009] It thus can be seen that under suitable conditions, absorbance isdirectly proportional to analyte concentration through Beer's law. Theconcentration of the analyte can be determined from the absorbancevalue, which in turn is calculated from the ratio of measured radiationtransmitted and measured radiation incident. In addition, a trueabsorbance value can be obtained by measuring a reference or blank mediasample and taking the ratio of the radiant power transmitted through theanalyte sample to that transmitted through the blank sample.

[0010] Ordinarily, the sample is transferred to a sample cell that iscontained within the analytical instrument (e.g., spectrophotometer)itself. An example of a conventional sample testing system is disclosedin U.S. Pat. No. 6,060,024. Samples are taken from test vessels and,using sampling pumps, carried over sampling lines and through samplingfilters. The samples are then transported either to a UV analyzercontaining six cells, to an HPLC system, or to a fraction collector.

[0011] Examples of UV-vis spectrophotometers are those available fromVarian, Inc., Palo Alto, Calif., and designated as the CARY™ Seriessystems. In particular, the Varian CARY 50™ spectrophotometer includes asample compartment that contains a sample cell through which a lightbeam or pulse passes. Several sizes of sample cells are available. Inaddition, the spectrophotometer can be equipped with a multi-cell holderthat accommodates up to eighteen cells. A built-in movement mechanismmoves the cells past the light beam.

[0012] In other recently developed systems, fiber-optics are being usedin conjunction with UV scans to conduct in-situ absorptionmeasurements—that is, measurements taken directly in the samplecontainers of either dissolution test equipment or sample analysisequipment. Fiber optic cables consist of, for example, glass fiberscoaxially surrounded by protective sheathing or cladding, and arecapable of carrying monochromatic light signals. A typical in-situfiber-optic method associated with dissolution testing involvessubmerging a dip-type fiber-optic UV probe in test media contained in avessel. A light beam (UV radiation) provided by a deuterium lamp isdirected through fiber-optic cabling to the probe. Within the probe, thelight travels through a quartz lens seated directly above a flowcell-type structure, the interior of which is filled with a quantity ofthe test media. The light passes through the test media in the flowcell, is reflected off a mirror positioned at the terminal end of theprobe, passes back through the flow cell and the quartz lens, andtravels through a second fiber-optic cable to a spectrometer.

[0013] For the previously described Varian CARY 50™ spectrophotometer, afiber-optic dip probe coupler is available to enable in-situ samplemeasurement methods and effectively replace the need for a sipperaccessory. This fiber optic coupler can be housed in thespectrophotometer unit in the place of the conventional sample cell. Thecoupler includes suitable connectors for coupling with the source andreturn optical fiber lines of a remote fiber-optic dip probe. The lightbeam from the light source of the spectrophotometer is directed tosource line of the dip probe, and the resulting optical signaltransmitted back to the spectrophotometer through the return line.

[0014] Fiber optics have also been employed in connection withsample-holding cells. For example, U.S. Pat. No. 5,715,173 discloses anoptical system for measuring transmitted light in which both a sampleflow cell and a reference flow cell are used. Light supplied from alight source is transmitted through an optical fiber to the sample flowcell, and also through a second optical fiber to the reference flowcell. The path of transmitted light from each flow cell is directedthrough respective optical fibers toward an optical detector, and iscontrolled by an optical path switcher in the form of a light selectingshutter or disk.

[0015] It is acknowledged by persons skilled in the art that, whenworking with an array of flow cells, sample cells, cuvettes, probes, andother instruments of optical measurement, and particularly in connectionwith fiber-optic components, there remains a need for efficiently andeffectively routing or distributing light energy to and from such samplecontainers. This need has been the subject of some developmentalefforts.

[0016] For instance, U.S. Pat. No. 5,526,451 discloses a fiber-opticsample analyzing system in which a plurality of cuvettes each have asource optical fiber and a return optical fiber. A device is providedfor selecting a source fiber to receive radiation for passage through aselected sample of one of the cuvettes, and for returning transmittedradiation from the selected cuvette through a selected return fiber to aspectrophotometer. The selection device includes a single rotatableretaining member supporting the respective ends of eight fiber-opticinput lines and eight corresponding fiber-optic output lines. Therespective ends of the fiber-optic lines are arranged in a ring aroundthe central axis of the retaining member. The eight input lines defineone half of the ring while the eight output lines define the other half.By this arrangement, each input line end affixed to the retaining memberhas a corresponding output line end affixed in diametrically oppositerelation along the ring. Rotation of the retaining member determineswhich pair of input and output lines are respectively aligned with aninput lens and an output lens disposed in spaced relation to theretaining member. A source beam passes through the input lens and intothe selected input line at the end supported by the retaining member.The source beam then travels through the input line and into the samplecuvette associated with that particular input line. From the samplecuvette, the transmitted beam travels through the output line associatedwith the selected input line and sample cuvette. This output lineterminates at its end supported by the retaining member. Since thisoutput end is aligned with the output lens spaced from the retainingmember, the transmitted beam passes through the output lens and isconducted to the analyzing means of the spectrophometer.

[0017] U.S. Pat. No. 5,112,134 discloses a vertical-beam photometricmeasurement system for performing enzyme-linked immunoabsorbent assay(ELISA) techniques. The system includes a light coupling andtransmission mechanism utilizing a cylindrical rotor and a fiber-opticdistributor. The mechanism receives light from a light assembly. Thecylindrical rotor includes an optical fiber having an input end locatedat its center, and an output end located near its periphery. As therotor rotates, the input end of the fiber of the rotor remainsstationary with respect to the light assembly, while the output endmoves around a circular path. The light output of the fiber of the rotoris received by a fiber optic distributor containing a multiplicity ofoptical fibers having their respective input ends arranged in a circulararray. As the rotor is indexed about its axis, the output end of itsfiber can be brought into alignment with successive fibers of thedistributor. On the output side of the distributor, the multiplicity offibers lead to a fiber manifold. The manifold aligns each fiber with acorresponding one of an array of assay sites. A detector board islocated below the assay sites. The detector board contains an array ofphotodetectors corresponding to the array of assay sites. Light from aselected fiber passes through a corresponding assay site and into acorresponding photodetector of the detector board. As in other systems,this system requires a plurality of photedetectors and is not capable ofrouting the incident light from each sample well to a single detectionmeans.

[0018] U.S. Pat. No. 6,151,111 also discloses a vertical-beamphotometric system in which a plate carrier sequentially advances an8×12 microplate through a measurement station. Each column of eightwells is scanned by light emitted from a bundle of eight correspondingdistribution optical fibers. Light supplied from a light source passesthrough a monochromator to a rotor assembly. Each of the eightdistribution fibers enables light from the rotor assembly to besequentially directed by a corresponding mirror vertically through acorresponding aperture, lens, and microplate well, and subsequently intoa corresponding photodetector lens. The rotor assembly consists of twomirrors positioned so as to bend light received by the rotor assembly180 degrees, after which the light can be directed into one of thedistribution fibers. The rotor can then be moved into alignment withanother distribution fiber.

[0019] U.S. Pat. No. 4,989,932 discloses a multiplexer for enabling thesampling of a number of different samples. The multiplexer contains astationary cylindrical outer body and a rotatable optical barreldisposed within the outer body. A primary inlet port is located on oneside of the outer body through which light is introduced into themultiplexer. A primary exit port is located on an opposing side of theouter body through which light exits the multiplexer for transmission toan apparatus for optically analyzing a sample. Pairs of ancillary inletand exit ports are disposed around the cylindrical wall of the outerbody, and are oriented radially (or transversely) with respect to thelongitudinal axis. The rotatable barrel contains a first mirror and lensassociated with the ancillary exit ports, and a second mirror and lensassociated with the ancillary inlet ports. A stepper motor is used torotate the barrel to successively align the mirrors and lenses with aselected pair of ancillary inlet and exit ports. Light transmittedthrough the primary inlet port along the longitudinal axis of themultiplexer is turned at a right angle by the first mirror, passesthrough the first lens, and exits the multiplexer through the selectedancillary exit port. From the selected ancillary exit port, the light istransmitted through a fiber-optic bundle to a sample and returns to themultiplexer through the corresponding selected ancillary inlet port.From the selected ancillary inlet port, the light passes through thesecond lens, is turned at a right angle by the second mirror, and exitsthe multiplexer along the longitudinal axis. Other pairs of ancillaryinlet and exit ports can be selected by rotating the barrel. In anotherembodiment disclosed in this patent, incoming light is received by anoptical rod that has an angled mirrored surface at its end. Rotation ofthe rod by a stepper motor positions the angled mirrored surface todirect the light into a selected fiber-optic bundle.

[0020] U.S. Pat. No. 5,804,453 discloses a system in which a fiber-opticbiosensor probe is inserted into a test tube. The probe receives a lightbeam from a light source and sends a testing signal to thephotodetectors of a spectrometer. Time division multiplexing anddemultiplexing are implemented to distribute light to and from severalbiosensors. Switching among inputs and outputs is controlled by an inputcontrol signal provided by an electronic clocked counter.

[0021] U.S. Pat. No. 5,580,784 discloses a system in which a pluralityof chemical sensors are associated with several sample vials andarranged between a light source and a photodetector. Optical fibers areused to direct radiation into each sensor, as well as to directemissions out from the sensors. A wavelength-tunable filter is combinedwith an optical multiplexer to direct radiation serially to each sensorthrough the fibers.

[0022] In view of the current state of the art, there is a continuingneed for improved means for efficiently and effectively routing ordistributing light energy to and from sample testing sites. It would betherefore be advantageous to provide an apparatus and method thatutilize mechanical components to effect indexing among several opticalinput and/or output channels in an efficient and controlled mannerwithout the need for costly optics-based switching components. Inparticular, it would be advantagous to provide an apparatus and methodthat enable analysis of multiple samples using only a single lightsource and a single detection means. Such an apparatus should bedesigned to minimize light loss and be compatible with a wide range ofoptical-based measurement systems. The present invention is provided toaddress these and other problems associated with the prior art.

SUMMARY OF THE INVENTION

[0023] According to one embodiment of the present invention, a sampleanalysis system comprises a plurality of media containers, a pluralityof sample test sites, a plurality of media sampling lines, a pluralityof optical source lines, a plurality of optical return lines, and anoptical input selection device. Each media sampling line is adapted fortransferring a quantity of media from a corresponding one of the mediacontainers to a corresponding one of the sample test sites. Each opticalsource line has an optical source line input end and an optical sourceline output end. Each optical source line output end communicates with acorresponding one of the sample test sites. Each optical return line hasan optical return line input end and an optical return line output end.Each optical return line input end communicates with a corresponding oneof the sample test sites. The optical input selection device isrotatable about a first axis, and comprises a first internal opticalfiber having a first input end and a first output end. The first inputend is disposed collinearly with the first axis. The first output end isdisposed at a radially offset distance from the first axis and isalignable with a selected one of the optical source line input ends.

[0024] Preferably, the system according to this embodiment alsocomprises a plurality of media return lines, each of which is adaptedfor transferring the quantity of test media from the correspondingsample test site back to the corresponding media container.

[0025] According another embodiment of the present invention, theoptical input selection device comprises a first rotary element and afirst stationary element. The first rotary element is rotatable aboutthe first axis, and comprises a first input end surface and an opposingfirst output end surface. The first input end of the first internaloptical fiber is exposed at the first input end surface, and the firstoutput end of the first internal optical fiber is exposed at the firstoutput end surface. The first stationary element is disposed adjacent tothe first output end surface, and has a plurality of circumferentiallyspaced first stationary element apertures. Each first stationary elementaperture is disposed at the radially offset distance from the firstaxis, and the first output end of the first internal optical fiber isalignable with a selected one of the first stationary element aperturesthrough rotation of the first rotary element.

[0026] According to yet another embodiment of the present invention, thesample analysis system also comprises an optical output selection devicerotatable about a second axis. The optical output selection devicecomprises a second internal optical fiber having a second input end anda second output end. The second input end is disposed at a radiallyoffset distance from the second axis, and is alignable with a selectedone of the return line output ends. The second output end is disposedcollinearly with the second axis. Preferably, the system furthercomprises a rotatable coupling mechanism interconnecting the opticalinput selection device and the optical output selection device, whereinrotation of the coupling mechanism causes simultaneous rotation of thefirst output end and the second input end.

[0027] According to still another embodiment of the present invention, asample analysis system comprises a mounting component and an opticalreceiving device, wherein each optical return line output end is fixedlysupported by the mounting component in optical alignment with theoptical receiving device.

[0028] The present invention advantageously provides a mechanical,rotary fiber-optic multiplexer (and demultiplexer) apparatus forselecting channels through which a beam or pulse of light is routed inan indexing manner. The apparatus comprises one, two, or more rotaryindexing devices. One of the rotary indexing devices demultiplexes abeam of light by distributing the light from a single, common outgoingor source line into a selected one of a plurality of outgoing or sourcechannels. The selection is accomplished by rotating the demultiplexingdevice into a position at which the common outgoing or source line canoptically communicate with the selected outgoing channel. The otherrotary indexing device, when employed in certain embodiments of theinvention, multiplexes a beam of light for transmission into a singleincoming or return line by selecting a selected one of a plurality ofincoming or return channels. The selection is accomplished by rotatingthe multiplexing device into a position at which the common incoming orreturn line can optically communicate with the selected incoming orreturn channel. In other embodiments, each incoming or return line isoptically aligned with a signal receiving means such as a photodetector,thereby eliminating the need for the second rotary indexing device andthe common incoming or return line.

[0029] When two such rotary devices are provided in this manner, theycan be mechanically interfaced so that rotation of one device concurswith rotation of the other device, with the result that the selection ofa certain channel of the one device concurs with the selection of acorresponding channel of the other device. For instance, if each deviceincludes twelve channels and thus twelve index positions, the selectionof the channel at index position 1 of the one device simultaneouslyresults in the selection of the channel at index position 1 of the otherdevice.

[0030] Each rotary device can comprise two fixed components (i.e., firstand second fixed components), a rotary component, and one or morebearings providing an interface between the fixed components and therotary component. The rotary component is interposed between the twofixed components. Each fixed component faces a respective end of therotary component. One of the fixed components (e.g., the first fixedcomponent) has an optical fiber at its axial center. The other fixedcomponent (e.g., the second fixed component) has a plurality of opticalfibers oriented in a circular arrangement about its axial center. Thenumber of optical fibers in the circular arrangement corresponds to thenumber of optical channels selectable by the apparatus of the invention.The rotary component has an optical fiber having one end located at theaxial center of the rotary component and another end located radiallyoutward with respect to the axial center. The centrally located end ofthe optical fiber of the rotary component is separated from thecentrally located optical fiber of the first fixed component by a verysmall air gap. The offset end of the optical fiber of the rotarycomponent is likewise separated from the plurality of optical fibers ofthe second fixed component by a very small air gap. These air gapsoptimize light transmission while minimizing light loss, and avoid thenecessity of using expensive additional optical components to couple therespective optical fibers of the fixed and rotary components. Indexedrotation of the rotary component with respect to the second fixedcomponent results in selective coupling between the offset end of theoptical fiber of the rotary component and each optical fiber of thesecond fixed component.

[0031] As indicated previously, the two rotary devices included with theapparatus rotate together through a mechanical interface. This interfacecan be accomplished through a suitable set of gears arranged such thatrotation of at least one gear results in rotation of both rotarydevices. For example, each rotary device could be provided with its owngear, and each of these gears could be placed in meshing engagement witha third gear. While manual rotation of the third gear in order to rotatethe other gears is possible, it is preferred that the third gear bepowered through connection to a motor or similarly automated device. Themotor could then be electronically controlled by suitable electronichardware and/or software. As an alternative to providing gears with eachrotary device, gear-like teeth could be formed on respective structuresof the rotary devices to eliminate additional gearing. In either case,the rotary devices of the apparatus can be rotated continuously withoutthe need to reverse rotation upon completion of the indexing of eachchannel provided. For instance, for a twelve-channel apparatus, thesampling interval from index position 1 to index position 2 isequivalent to the sampling interval from index position 12 to indexposition 1.

[0032] As an alternative, the first rotary device utilized to select anoutgoing channel is provided, but the second rotary device utilized toselect an incoming channel is eliminated in favor of suitably collectinga bundle of optical return fibers constituting the incoming channels ata fixed position at which the ends of the fibers are optically alignedwith the receiving window of a optical detection device.

[0033] The invention as just described offers advantages whenincorporated into any system that includes one or more light sources andone or more devices adapted for receiving light energy from the lightsources. In such systems, the mechanical multiplexing/demultiplexingfunctions realized by the present invention are useful in networking oneor more light signals from selected light sources to selected receiverdevices. The invention also offers advantages when incorporated into anysystem that uses optics to route optical signals over several lines orchannels between a single light source and a single detector. An exampleof this latter system is a UV-vis spectrophotometer, which is generallydesigned to conduct UV scans on prepared samples. It is often desirableto scan a multitude of samples. In accordance with the presentinvention, each sample can be held in a test vessel or a suitable cellor well, or in any other suitable sample holding or containment means,and fiber-optic input and output lines can be brought into operativecommunication with each sample test site, or with each probe associatedwith the sample test site. In this manner, each cell, probe, vessel ortest site respectively becomes associated with one of the channels ofthe apparatus of the invention, and hence becomes associated with thecorresponding index positions of the rotary device or devices of theapparatus. Accordingly, the selection of index position 1 of each rotarydevice, for example, corresponds to the selection of test vessel 1, cell1, and so on.

[0034] The fiber-optic channel selecting apparatus as described hereincan be directly integrated into the design of an optical-based samplemeasurement and/or analysis system or instrument, such as aspectroscopic apparatus. An example of a spectroscopic apparatus is aspectrophotometer.

[0035] According to another aspect of the present invention, a methodfor acquiring data from samples comprises the following steps. Aplurality of samples are respectively disposed in a plurality of mediacontainers. A plurality of test sites are provided. A plurality ofoptical source lines are provided such that each source linecommunicates with a corresponding one of the test sites. A plurality ofoptical return lines are provided such that each return linecommunicates with a corresponding one of the test sites. A plurality ofmedia sampling lines fluidly interconnect corresponding media containersand test sites. A test site, and its corresponding source line, returnline and media container, are selected by rotating a fiber-optic channelselecting apparatus to a position at which the selected source linecommunicates with a light source. The sample disposed in the selectedmedia container is transferred through its corresponding media samplingline to the selected test site. An optical signal of a first intensityis sent through the selected source line to the selected test site toexpose the sample transferred to the selected test site. An opticalsignal of a second intensity is emitted from the selected test site andtravels through the selected return line. This process can be repeatedfor additional samples of the plurality of samples provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036]FIG. 1 is a perspective view of a fiber-optic channel selectionapparatus provided in accordance with the present invention;

[0037]FIG. 2 is a side elevation view of the apparatus illustrated inFIG. 1;

[0038]FIG. 3 is a top plan view of the apparatus illustrated in FIG. 1;

[0039]FIG. 4 is a rear elevation view of the apparatus illustrated inFIG. 1 showing the interconnection of rotary devices provided inaccordance with one embodiment of the present invention;

[0040]FIG. 5A is a cross-sectional view of a rotary device fordistributing a light beam or signal from a single input to one or morefiber-optic channels in accordance with the present invention;

[0041]FIG. 5B is a cross-sectional view of a rotary device fordistributing light beams or signals from one or more fiber-opticchannels to a single output in accordance with the present invention;

[0042]FIG. 6A is a cross-sectional view of an optical input selectiondevice provided with the apparatus illustrated in FIGS. 1-4, includingthe rotary device illustrated in FIG. 5A;

[0043]FIG. 6B is cross-sectional view of an optical output selectiondevice provided with the apparatus illustrated in FIGS. 1-4, includingthe rotary device illustrated in FIG. 5B;

[0044]FIG. 7A is a plan view illustrating either the input side of theoptical input selection device illustrated in FIG. 6A or the output sideof the optical output selection device illustrated in FIG. 6B;

[0045]FIG. 7B is a plan view illustrating either the output side of theoptical input selection device illustrated in FIG. 6A or the input sideof the optical output selection device illustrated in FIG. 6B;

[0046]FIG. 7C is a perspective view of either of the optical inputselection device illustrated in FIG. 6A or the optical output selectiondevice illustrated in FIG. 6B;

[0047]FIG. 8 is a schematic diagram of an analytical testing and dataacquisition system in which the apparatus or portions thereofillustrated in FIGS. 1-7C is incorporated;

[0048]FIG. 9 is a schematic diagram of one type of a liquid sampleanalysis system in which the apparatus or portions thereof illustratedin FIGS. 1-7C is incorporated in accordance with the present invention;

[0049]FIG. 10 is a perspective view of a media preparation/testingapparatus suitable for use in connection with the systems illustrated inFIGS. 8 and 9;

[0050]FIG. 11 is a schematic diagram of another analytical testing anddata analysis system suitable for use in the present invention;

[0051]FIG. 12A is a front elevation view of a fiber-optic bundlemounting component provided with the system illustrated in FIG. 11; and

[0052]FIG. 12B is a cross-sectional side view of the mounting componentillustrated in FIG. 12A.

DETAILED DESCRIPTION OF THE INVENTION

[0053] In general, the term “communicate” (e.g., a first component“communicates with” or “is in communication with” a second component) isused herein to indicate a structural, functional, mechanical, optical,or fluidic relationship between two or more components or elements. Assuch, the fact that one component is said to communicate with a secondcomponent is not intended to exclude the possibility that additionalcomponents may be present between, and/or operatively associated orengaged with, the first and second components.

[0054] As used herein, the term “multiplexer” is broadly defined toindicate a system or device that includes a plurality of independent,individual input lines or channels and a single output line or channel(i.e., a common path or bus). One of the input lines can be selected sothat its value or signal is transmitted or routed over the output line.Thus, the multiplexer could also be referred to as a data selector. Inaddition, the term “demultiplexer” is broadly defined herein asimplementing the converse function of the multiplexer. That is, ademultiplexer is a system or device that includes one input line orchannel (i.e., a common path or bus) and a plurality of output lines orchannels. One of the output lines is selected to receive the value orsignal provided by the input line. Thus, the demultiplexer could also bereferred to as a data distributor. These terms, as used herein, aretherefore intended to have a broader meaning than, for instance, themeanings typically understood by persons associated with thecommunications or electronics industries, wherein the terms are oftenrestricted to meaning a system in which all elements of a given signalare observed simultaneously. For convenience, the term “multiplexer” or“multiplexing apparatus” as used hereinafter is intended to cover adevice or system that includes a multiplexer and/or a demultiplexer.

[0055] As used herein, the terms “beam,” “pulse,” and “optical signal”are intended to be interchangeable to indicate that the presentinvention is applicable to the transmission of light energy by bothcontinuous and non-continuous methods.

[0056] As used herein, the terms “aperture” and “bore” are usedinterchangeably to denote any opening through which light energy can betransmitted with an acceptable degree of efficiency and an acceptableminimum of light loss. Such an opening can include an optical fiber forthese purposes as well. Whether the term “aperture” or “bore” is moreappropriate could, for instance, depend on the thickness of thestructural body through which the opening runs, but in any case the twoterms are considered herein to be interchangeable.

[0057] Referring now to FIGS. 1-4, an optical signal multiplexingapparatus, generally designated 10, is illustrated in accordance withthe present invention. Multiplexing apparatus 10 comprises an enclosure12 mounted to a base 14. Two rows of apertures (see FIG. 3), generallydesignated 16 and 18, respectively, are formed on a top surface 12A ofenclosure 12. Two corresponding rows of fiber optic cable ferrules orfittings generally designated 21 and 23, respectively, (see FIG. 1) aremounted in these apertures 16 and 18. Individual fiber-optic sourcelines OSL₁-OSL_(n) (where, in the illustrated exemplary embodiment, n=8)extend through the respective fittings of row 23 (and apertures 18), andindividual fiber-optic return lines ORL₁-ORL_(n) extend through therespective fittings of the other row 21(and apertures 16). In FIGS. 1and 3, only the first pair of optical source and return lines, opticalsource line OSL₁ and optical return line ORL₁, are shown. In FIG. 2, therespective bundles of optical source lines OSL₁-OSL_(n) and opticalreturn lines ORL₁-ORL_(n) are schematically depicted by large arrows toindicate generally the direction of optical signals into and out frommultiplexing apparatus 10.

[0058] Portions of enclosure 12 are removed in FIGS. 1-4 to illustratethe interior components disposed within enclosure 12. The primaryoperative interior components are two rotary indexing devices. Onerotary device is referred to herein as an optical source line selectordevice, generally designated 80, and the other rotary device is referredto as an optical return line selector device, generally designated 130.

[0059] Source and return line selector devices 80 and 130 are situatedadjacent to one another and are supported in fixed relation to eachother, for example, by two axially spaced mounting blocks 26 and 28 thatextend upwardly from base 14. A ferrule or input fitting 31 is connectedto an input end of source line selector device 80. A circular array offittings, generally designated 33, are connected to an output end ofsource line selector device 80. Another circular array of fittings,generally designated 35, are connected to an input end of return lineselector device 130. A ferrule or output fitting 37 is connected to anoutput end of return line selector device 130. A common source line orinput bus IB is connected to input fitting 31, and a common return lineor output bus OB is connected to output fitting 37. As just described,each individual fiber-optic source line OSL₁-OSL_(n) runs through acorresponding fitting 23 of aperture row 18, and each individual returnline ORL₁-ORL_(n) runs through fittings 21 mounted to aperture row 16.Although not specifically shown in FIG. 1 for clarity, each individualfiber optic source line OSL₁-OSL_(n) is connected to a corresponding oneof fittings 33 of source line selector device 80, and each individualreturn line ORL₁-ORL_(n) is likewise connected to a corresponding one offittings 35 of return line selector device 130. As described more fullybelow, source line selector device 80 functions to select which one ofthe fiber-optic source lines OSL₁-OSL_(n) is optically coupled to inputbus IB over a given interval of time. Return line selector device 130functions to select which one of the fiber-optic return linesORL₁-ORL_(n) is optically coupled to output bus OB over the sameinterval of time.

[0060] As best shown in FIGS. 3 and 4, multiplexing apparatus 10 furthercomprises a means for causing both source line selector device 80 andreturn line selector device 130 to rotate simultaneously and in anindexing fashion. Preferably, the means is provided in the form of apowered mechanism adapted to transfer rotational force through a forcetransmission mechanism. In the exemplary embodiment illustrated in FIGS.1-4, the powered mechanism is a motor 40 (such as, for example, a DCstepper motor) that causes a shaft 42 to rotate through programmedincrements. The transmission mechanism includes an arrangement of gearwheels 45, 47 and 49. Gear wheel 45 is mounted to shaft 42 and thusrotates about the axis of shaft 42. Gear wheel 47 is mounted to sourceline selector device 80 and rotates about an axis L₁ of source lineselector device 80 (see FIG. 4). Gear wheel 49 is mounted to return lineselector device 130 and rotates about an axis L₂ of return line selectordevice 130. Gear wheels 47 and 49 are disposed in meshing engagementwith gear wheel 45. Accordingly, clockwise rotation of gear wheel 45results in counterclockwise rotation of both gear wheels 47 and 49.Conversely, counterclockwise rotation of gear wheel 45 results inclockwise rotation of both gear wheels 47 and 49. Moreover, gear wheels47 and 49 are similarly sized and have the same number of teeth. As aresult, rotation of gear wheel 45 through a given incremental arc lengthcauses rotation of both gear wheels 47 and 49 through anotherproportional incremental arc length. The arc length through which gearwheel 47 rotates is the same as the arc length through which gear wheel49 rotates.

[0061] As appreciated by persons skilled in the art, multiplexingapparatus 10 can be provided with means for verifying the positions ofthe various rotating components. For example, primary positionverification can be effected by providing an optical encoder (not shown)that is focused on shaft 42 of motor 40. As a secondary mode of positionverification, Hall effect sensors (not shown) can be provided tointerface with a magnet (not shown) mounted on each gear wheel 47 and 49respectively associated with source line selector device 80 and returnline selector device 130. With respect to each source line selectordevice 80 and return line selector device 130, each corresponding set ofHall effect sensors would be mounted at each index position, such as bymounting the sensors in a circular array on a separate disks thatrotates with corresponding barrel 85 or 135 in parallel with the magnetmounted to corresponding gear wheel 47 or 49.

[0062] Referring now to FIGS. 5A-7C, details of source line selectordevice 80 and return line selector device 130 are illustrated. Referringspecifically to FIG. 5A, source line selector device 80 comprises arotary element or barrel 85 that is rotatable about its central axis L₁.Barrel 85 includes an outer lateral surface 85A, an input end surface85B, and an output end surface 85C. Gear wheel 47 is fitted around theperiphery of outer lateral surface 85A. Gear wheel 47 is either aseparate component or comprises teeth formed around barrel 85. Aninternal bore 87 extends through the body of barrel 85, and has an inputbore end 87A opening at input end surface 85B and an output bore end 87Bopening at output end surface 85C. Input bore end 87A is coincident withaxis L₁, and thus the position of input bore end 87A in relation to axisL₁ does not change during rotation of barrel 85. Output bore end 87B, onthe other hand, is disposed at a location on output end surface 85C thatis offset from axis L₁ by a radial offset distance equal to radius R.Rotation of barrel 85 about axis L₁ therefore results in rotation ofoutput bore end 87B along a circular path of radius R, as defined onoutput end surface 85C with respect to axis L₁. An internal opticalfiber 90 (see FIG. 6A) extends throughout internal bore 87. Internaloptical fiber 90 terminates at an input fiber end 90A (see FIG. 6A)located at input bore end 87A, and terminates at an output fiber end 90B(see FIG. 6A) located at output bore end 87B. Thus, input fiber end 90Ais coincident with axis L₁ and output fiber end 90B is offset from axisL₁ by radial offset distance (or radius) R. Rotation of barrel 85 aboutaxis L₁ does not affect the position of input fiber end 90A, but resultsin a circumferential change in the position of output fiber end 90B withrespect to axis L₁.

[0063] Referring to FIG. 6A, source line selector device 80 is designedto permit rotational indexing of barrel 85 about axis L₁. Through thisrotational movement, output fiber end 90B can be selectively positionedat one of a plurality of equally spaced index locations around acircumference on output end surface 85C. This circumference is swept outby the conceptual end point of radius R in relation to axis L₁. In orderto implement source fiber “channel” or line selection, barrel 85 rotateswith respect to some type of stationary member that includes a number offixed-position optical reception points corresponding to the pluralityof index locations. In FIG. 6A, for example, the channel selection isimplemented according to the invention by providing a stationary opticalreception member. In the present embodiment, the stationary opticalreception member is a bearing sleeve or cap 95 disposed at the outputside of barrel 85. A bearing 105 provides an interface between rotatablebarrel 85 and stationary bearing sleeve 95. As illustrated in FIG. 6A,bearing 105 can be a roller bearing of conventional design that includesan inner ring 105A, an outer ring 105B, and a series of balls 107contacting the respective, opposing raceways of inner ring 105A andouter ring 105B. As understood by persons skilled in the art, balls 107typically are interposed between inner ring 105A and outer ring 105B andin a circumferentially spaced arrangement through the use of a retainingelement (not shown) forming some type of frame, cage, or carriage aroundeach ball 107. Inner ring 105A firmly contacts (such as by pressfitting) lateral outer surface 85A of barrel 85, while outer ring 105Bfirmly contacts at least the inner surface of an annular section 95A ofbearing sleeve 95. By this arrangement, inner ring 105A rotates withbarrel 85 while outer ring 105B remains in a fixed position withstationary bearing sleeve 95. It will be understood that bearing 105could be either a ball bearing or a needle bearing, or some other typeof bearing that permits barrel 85 to rotate in a stable manner withrespect to bearing sleeve 95. That is, rotatable needle elements couldbe substituted for balls 107 illustrated in FIG. 6A.

[0064] In addition to its annular section 95A, bearing sleeve 95includes a plate section 95B transversely oriented with respect to axisL₁ of source line selector device 80. Plate section 95B is immediatelyadjacent to output end surface 85C of barrel 85. Plate section 95Bincludes a plurality of apertures 97 (only two of which are shown inFIG. 6A) arranged in a circular array of radius R with respect to axisL₁. These apertures 97 constitute the previously describedfixed-position optical reception points. The actual number of apertures97 corresponds to the number of indices at which output fiber end 90B ofinternal optical fiber 90 can be selectively positioned, and accordinglycorresponds to the number of individual optical channels or lines intowhich an optical signal traveling through internal optical fiber 90 frominput fiber end 90A can be selectively directed through output fiber end90B. The specific number of apertures 97 (and hence the specific numberof individual optical channels and index positions) will depend on thenumber of test sites to which optical source signals are to be sent.Besides the test sites that contain analytical samples, one or more ofthese test sites could hold reference or control samples (e.g., sourcesfor obtaining blank or standard measurement data). In the example shownin FIG. 7B, plate section 95B of bearing sleeve 95 includes an array ofeight apertures 97 to handle eight separate optical channels or lines.It will be understood, however, that more or less apertures 97 could beprovided, again depending on the number of separate optical channels.

[0065] The specific provision of bearing 105 and bearing sleeve 95, inthe arrangement and design illustrated in FIG. 6A, ensures that anylight loss from the light conducting components of source line selectordevice 80 is negligible. The size of the air gap between output endsurface 85C of barrel 85 and plate section 95B of bearing sleeve 95 ispreset to provide optimal light transmission. Annular section 95A andplate section 95B of bearing sleeve 95 cooperatively form a shoulderaround bearing 105 and output end surface 85C to prevent light losses.In furtherance of the purpose of preventing light loss in thisparticular arrangement, it is preferable that the axial edges of innerring 105A and outer ring 105B of bearing 105 facing plate section 95B ofbearing sleeve 95 be substantially flush with output end surface 85C ofbarrel 85.

[0066] Although source line selector device 80 and its barrel 85 are notexpected to encounter axial thrust forces during the operation ofmultiplexing device 10, source line selector device 80 can furtherinclude a second bearing 125 and corresponding bearing sleeve 115mounted at the input side, as also shown in FIG. 6A. The design andarrangement of input-side bearing 125 and bearing sleeve 115 can besimilar to those of output-side bearing 105 and bearing sleeve 95.Input-side bearing sleeve 115 thus includes an annular section 115A anda plate section 115B. As one principal difference, however, input-sidebearing sleeve 115 includes only one aperture 117 formed in its platesection 115B (see also FIG. 7A). This single aperture 117 is situatedcoincident with axis L₁ and is immediately adjacent to input fiber end90A of internal optical fiber 90. The inclusion of input-side bearing125 and bearing sleeve 115 lends stability to the indexing movements ofbarrel 85 and overall operation of source line selector device 80, andfurther facilitates the optical coupling of internal optical fiber 90 toinput bus IB (see FIG. 1). Input-side bearing 125 can comprise balls 127interposed between an inner ring 125A and an outer ring 125B.

[0067] Referring to FIG. 5B, return line selector device 130 comprisesfeatures similar to those of source line selector device 80 although, asshown in FIG. 1, the axial positions of the input and output sides ofreturn line selector device 130 are reversed in comparison to those ofsource line selector device 80. Specifically, return line selectordevice 130 comprises a rotary element or barrel 135 rotatable about itscentral axis L₂. Barrel 135 includes an outer lateral surface 135A, aninput end surface 135B, and an output end surface 135C. Gear wheel 49 isfitted around the periphery of outer lateral surface 135A. Gear wheel 49is either a separate component or comprises teeth formed around barrel135. An internal bore 137 extends through the body of barrel 135, andhas an input bore end 137A opening at input end surface 135B and anoutput bore end 137B opening at output end surface 135C. Input bore end137A is disposed at a location on input end surface 135B that is offsetfrom axis L₂ by a radial offset distance equal to radius R. Rotation ofbarrel 135 about axis L₂ therefore results in rotation of input bore end137A along a circular path of radius R defined on input end surface 135Bwith respect to axis L₂. Output bore end 137B, on the other hand, iscoincident with axis L₂ such that its position in relation to axis L₂does not change during rotation of barrel 135. An internal optical fiber140 extends throughout internal bore 137. Internal optical fiber 140(see FIG. 6B) terminates at an input fiber end 140A located at inputbore end 137A, and terminates at an output fiber end 140B located atoutput bore end 137B. Thus, input fiber end 140A is offset from axis L₂by radial offset distance (or radius) R and output fiber end 140B iscoincident with axis L₂. Rotation of barrel 135 about axis L₂ does notaffect the position of output fiber end 140B, but results in acircumferential change in the position of input fiber end 140A withrespect to axis L₂.

[0068] Referring to FIG. 6B, return line selector device 130 enablesrotational indexing of barrel 135 about axis L₂ in a manner analogous tosource line selector device 80. Through the rotational movement effectedby return line selector device 130, its input fiber end 140A can beselectively positioned at one of a plurality of equally spaced indexlocations around a circumference of radius R defined on input endsurface 135B. In order to implement return fiber “channel” or lineselection, return line selector device 130 includes a stationary bearingsleeve 145 disposed at the output side of barrel 135. As in the case ofsource fiber selector device 80, barrel 135 rotates with respect tobearing sleeve 145. A bearing 155 provides an interface betweenrotatable barrel 135 and stationary bearing sleeve 145. Bearing 155 canbe provided in the form of a roller bearing that includes an inner ring155A, an outer ring 155B, and a series of balls 157 or needles accordingto conventional designs. Inner ring 155A rotates with barrel 135 whileouter ring 155B remains in a fixed position with stationary bearingsleeve 145.

[0069] Bearing sleeve 145 of return line selector device 130 comprisesan annular section 145A coaxially disposed around bearing 155 and aplate section 145B transversely oriented with respect to axis L₂ ofreturn line selector device 130. Plate section 145B is immediatelyadjacent to input end surface 135B of barrel 135 with an air gaptherebetween, which is dimensioned for optimal optical transmission.Annular section 145A and plate section 145B of bearing sleeve 145cooperatively form a shoulder around bearing 155 and input end surface135B. This arrangement of bearing 155 and bearing sleeve 145 ensuresthat any light loss from the light conducting components of return lineselector device 130 is negligible. In furtherance of the purpose ofpreventing light loss in this particular arrangement, it is preferablethat the axial edges of inner ring 155A and outer ring 155B of bearing155 facing plate section 145B of bearing sleeve 145 be substantiallyflush with input end surface 135B of barrel 135.

[0070] Plate section 145B includes a plurality of apertures 147 (onlytwo of which are shown in FIG. 6B) arranged in a circular array ofradius R with respect to axis L₂. These apertures 147 constitutefixed-position optical coupling points between the individual returnfibers ORL₁-ORL_(n) and input fiber end 140A of internal optical fiber140. The actual number of apertures 147 corresponds to the number ofindices at which input fiber end 140A can be selectively positioned, andaccordingly corresponds to the number of individual optical channels orlines from which an optical signal can be selectively directed intoinput fiber end 140A. The specific number of apertures 147 (and hencethe specific number of individual optical channels and index positions)will depend on the number of sites or detection areas from which opticalreturn signals are to be received.

[0071] As also shown in FIG. 6B, return line selector device 130 canfurther include a second bearing 175 and corresponding bearing sleeve165 mounted at the output side. The design and arrangement ofoutput-side bearing 175 and bearing sleeve 165 can be similar to thoseof input-side bearing 105 and bearing sleeve 95. Output-side bearingsleeve 165 thus includes an annular section 165A and a plate section165B. Output-side bearing sleeve 165, however, includes only oneaperture 167 formed in its plate section 165B. This single aperture 167is situated coincident with axis L₂ and is immediately adjacent tooutput fiber end 140B of internal optical fiber 140 and, on the otherside, to output bus OB (see FIG. 1). Output-side bearing 175 cancomprise balls 177 interposed between an inner ring 175A and an outerring 175B.

[0072]FIG. 7A illustrates plate section 115B and single aperture 117 ofinput-side bearing sleeve 115 of source line selector device 80. FIG. 7Billustrates plate section 95B and multiple apertures 97 of output-sidebearing sleeve 95 of source line selector device 80. FIG. 7C illustratesinput-side bearing sleeve 115, output-side bearing sleeve 95, andbearings 105 and 125 assembled onto barrel 85 of source line selectordevice 80. It will be understood that FIGS. 7A-7C are likewiserepresentative of the structure of return line selector device 130, butwith the input and output sides reversed. That is, FIG. 7A couldrepresent plate section 165B and single aperture 167 of output-sidebearing sleeve 165 of return line selector device 130, and FIG. 7B couldrepresent plate section 145B and multiple apertures 147 of input-sidebearing sleeve 145 of return line selector device 130. Likewise, FIG. 7Ccan be considered as illustrating input-side bearing sleeve 145,output-side bearing sleeve 165, and bearings 155 and 175 assembled ontobarrel 135 of return line selector device 130.

[0073] According to another aspect of the invention, FIG. 8 illustratesthe general features of an analytical testing and data acquisitionsystem, generally designated 200, in which multiplexer apparatus 10 canadvantageously operate. In addition to multiplexer apparatus 10,analytical testing system 200 comprises a light source, generallydesignated 210, a data encoding or analytical signal generating systemor arrangement, generally designated 220, and an optical signalreceiving device or system generally designated 230.

[0074] Light source 210 can be any type of suitable continuous ornon-continuous optical source. Non-limiting examples include deuteriumarc lamps, xenon arc lamps, quartz halogen filament lamps, and tungstenfilament lamps. In one specific example, a pulsed light source such as axenon flash lamp could be employed to emit very short, intense bursts oflight. This type of lamp flashes only when acquiring a data point, ascompared to a diode array that exposes the sample to the entirewavelength range with each reading and potentially causes degradation ofphotosensitive samples. As described in commonly assigned U.S. Pat. No.6,002,477, because it emits light on a non-continuous basis, the xenonflash lamp does not require a mechanical means such as a chopper forinterrupting the light beam during measurement of a dark signal. Onespecific example of a xenon flash lamp that is capable of acquiringeighty data points per second is employed in CARY™ Seriesspectrophotometers commercially available from Varian, Inc, Palo Alto,Calif.

[0075] Data encoding or analytical signal generating system 220 cancomprise any device or system adapted to contain and expose one or moresamples to the light energy supplied by light source in order to encodeinformation about that sample as the light passes through the sample andthe sample is irradiated. For example, data encoding system couldconstitute an array of test sites F₁-F_(n) such as sample measurementand/or holding sites. These test sites F₁-F_(n) can be defined by avariety of sample measurement/containment components, such as solidsample holders, sample containers or cells, flow cells, test vessels,tanks, pipes, the wells of a quartz microtitre plate or similarmicrocells capable of transmitting light, and specially designedfiber-optic probes.

[0076] Signal receiving device or system 230 could be any type ofinstrument or system of instruments adapted to receive and process theoptical signals supplied by data encoding device 220. The specificproperty of the sample substance to be analyzed will dictate the type ofequipment or instrumentation used to analyze samples taken from, forexample, test vessels V₁-V₆ shown in FIG. 9. Moreover, the variouscomponents comprising signal receiving device 230 will depend on thetype of analytical signal to be measured and detected. If the desiredanalytical signal is the intensity of light radiation absorbed byanalytes at each test site F₁-F_(n), absorbance values can be calculatedin order to determine the concentration of the target substance (i.e.,the analyte of interest). For this purpose, signal receiving device 230in FIG. 8 can comprise a UV-vis spectrophotometer. The invention,however, is not limited to any specific design of spectrophotometer.Possible configurations for the spectrophotometer include those thatutilize single detectors or multi-channel detectors, those that areadapted to perform single-beam or double-beam measurements, those thatare adapted to perform horizontal-beam or vertical-beam measurements,and those that can perform measurements of fixed wavelength or of theentire absorption spectra for the sample. Moreover, for the purpose ofthe present disclosure, the terms “signal receiving device or system”and “sample analyzing system” are intended to encompass any analyzingequipment compatible with the systems and methods described herein. Suchequipment may include, but is not limited to, HPLC, spectrometers,photometers, spectrophotometers, spectrographs, and similar equipment.In the case of a spectrophotometer, as shown in FIG. 9, signal receivingdevice 230 typically includes light source 210, a wavelength selector232 or similar device, a radiation detector 234 such as a photoelectricdetector or transducer, a signal processor 236, and a readout device238.

[0077] Referring to the schematic depiction of analytical testing anddata acquisition system 200 illustrated in FIG. 8, light source 210optically communicates with source line selector device 80 ofmultiplexing apparatus 10 via input bus IB, and optical signal receivingdevice 230 optically communicates with return line selector device 130via output bus OB. In the present 25 embodiment, data encoding system220 comprises a set of sample measurement components or test sitesF₁-F_(n) (e.g., flow cells, sample cells, test vessels, or the like),each of which is adapted to contain or provide a target for a sample tobe analyzed. Source line selector device 80 optically communicates withsample measurement components F₁-F_(n) via the set of optical sourcelines OSL₁-OSL_(n), respectively, and return line selector device, 130optically communicates with sample measurement components F₁-F_(n) via aset of optical return lines ORL₁-ORL_(n), respectively. For clarity,only four each of optical source lines OSL₁-OSL_(n,), sample measurementcomponents F₁-F_(n), and optical return lines ORL₁-ORL_(n) are shown inFIG. 8. By this arrangement, each sample measurement component F₁-F_(n)can receive an incident light input of an initial intensity P₀ fromlight source over a corresponding optical source line OSL₁-OSL_(n), andsubsequently transmit a light output of an intensity P to optical signalreceiving device for processing and readout over a corresponding opticalreturn line OSL₁-OSL_(n). As described previously, respective internaloptical fibers 90 and 140 of source and return line selector devices 80and 130 are rotatably indexed in mutual synchronization. As a result,the selection of optical source line OSL₁, for example, to carry thesource signal from internal optical fiber 90 of source line selectordevice 80 to sample measurement component F₁ concurs with the selectionof optical return line ORL₁ to carry the attenuated signal transmittedfrom sample measurement component F₁ to internal optical fiber 140 ofreturn line selector device 130.

[0078] Referring now to FIG. 9, a specific application of analyticaltesting and data acquisition system 200 is illustrated. A scientific,optical-based sample analysis system (such as, for example, adissolution system), generally designated 250, comprises multiplexingapparatus 10, a media sampling system generally designated 260, a mediapreparation/testing apparatus generally designated 300, and a sampleanalyzing apparatus or signal receiving device 230 that in someembodiments houses light source 210. Media sampling system 260 includes,or at least communicates with, data encoding system 220. Data encodingsystem 220 includes a set F of sample measurement components F₁-F₆ suchas, for example, flow cells. A pair of optical source and return linesare coupled to each sample measurement component F₁-F₆, respectively.

[0079] In FIG. 9, the optical source lines are collectively designatedOSL, and the optical return lines are collectively designated ORL. Eachsample measurement component F₁-F₆ and its corresponding fiber-opticcomponents cooperatively enable an analytical signal to be generated ator within sample measurement component F₁-F₆ and transmitted to sampleanalyzing apparatus 230 for determination of the absorbance value of thesampled analytes.

[0080] In general terms, media sampling system 260 can be any systemadapted for selectively transferring media samples from a plurality of(e.g., six) test vessels V₁-V₆ over a bundle of media sample lines SL toa corresponding number of sample measurement components F₁-F₆ and theirrespective internal target or detection areas. Test vessels V₁-V₆ areused to hold liquid media that contain the components of, for example, adissolved pharmaceutical drug product, such as therapeutically activeparticles (i.e., the analytes of interest) and excipients. Preferably,after measurements have been taken using multiplexing apparatus 10 andlight source 210, media sampling system 260 is also adapted to returnthe media samples back to test vessels V₁-V₆ over a bundle ofcorresponding media return lines RL. Media sampling system 260 can alsobe adapted to handle calibration of flow cells F₁-F₆ by employing, forexample, a blank sample media vessel BV and/or standard sample mediavessel SV and appropriate components for routing blank media andstandard media through each flow cell F₁-F₆ to obtain reference orcalibration data. Blank sample media vessel BV is used to hold blankmedia, which does not contain any analytes. Standard sample media vesselSV is used to hold the standard media, which contains a referencesubstance having one or more known properties such as analyteconcentration. Test vessels V₁-V₆, blank sample media vessel BV, andstandard sample media vessel SV can all be mounted in an array on avessel plate that is integrated with a media preparation apparatus,generally designated 300 in FIG. 9. As appreciated by persons skilled inthe art, a media sampling system 260 suitable for use in connection withany of the systems, devices, and apparatuses described hereinabove caninclude pumps, valves, tubing, and other liquid handling components asappropriate.

[0081] Media preparation/testing apparatus 300 can be any apparatusadapted to implement the various tasks associated with optical-basedsample anaylsis and testing (for example, dissolution testing), and canbe automated or semi-automated. Ordinarily, media preparation/testingapparatus 300 provides means for mounting media vessels V₁-V₆, BV andSV. Typically, when carrying out dissolution testing, solvents are addedto each vessel, as are the dosage units to be tested. The resultingdissolution media contents in each vessel are heated and agitated asrequired by the particular testing protocol being followed. As thedosage units are dissolving, samples can be taken and routed to samplemeasurement components F₁-F₆ using media sampling system 260.

[0082] Referring now to FIG. 10, an example of a suitable embodiment ofmedia preparation/testing apparatus 300 is illustrated. Mediapreparation apparatus 300 generally includes, by way of example, a mainhousing or head assembly 311 containing a programmable systems controlmodule. Head assembly 311 is situated above a vessel plate 313 and awater bath container 315, and is typically motor-driven for verticalmovement toward and away from vessel plate 313. Peripheral elementslocated on head 311 include an LCD display 317 for providing menus,status and other information; a keypad 319 for providing user-inputtedoperation and control of spindle speed, temperature, test start time,test duration and the like; and readouts 321 for displaying informationsuch as RPM, temperature, elapsed run time, or the like. Vessel plate313 supports a plurality of vessels V extending into the interior ofwater bath container 315. One of vessels V can be utilized as blankvessel BV, another as standard vessel SV, and the rest as test vesselsV₁-V₆. A typical top-view arrangement of test vessels V₁-V₆, blankvessel BV, and standard vessel SV on vessel plate 313 is shown in FIG.9. Water must be heated and circulated through water bath container 315by means such as external heater and pump modules (not shown), which maybe combined into a single heater/circulator module. Water bath container315 thus requires a fluid transfer means such as tubing 316, as well asa drain line 329 and valve 331. Alternatively, media preparation/testingapparatus 300 can be a waterless design in which each vessel V isdirectly heated by some form of heating element disposed in thermalcontact with the wall of vessel V. As also shown in FIG. 10, a manifoldblock 335 integrating sample measurement component set F can be mounted“on-board” media preparation/testing apparatus 300 if desired.

[0083] Vessels V are typically locked and centered in place on vesselplate 313 by means such as ring lock devices or clamps 342. A stirringelement including a motor-driven spindle 343A and a paddle, basket orother appropriate component 343B operates in each vessel V. Individualclutches 345 can be provided to alternately engage and disengage powerto each spindle 343A. A dosage delivery module 347 is used to preloadand drop dosage units (e.g., tablets) into each vessel V at prescribedtimes and bath (or vessel) temperatures. An automated assembly orsampling manifold 349 lowers and raises sampling cannulas 351 and returncannulas 353 into and out of each respective vessel V. Automatedassembly 349 can also be vertically movable between head assembly 311and vessel plate 313. Sampling cannulas 351 and return cannulas 353operate in conjunction with a bidirectional peristaltic pump (notshown), and are used during a media preparation or testing procedure toperiodically withdraw samples from the vessel media. Samples could alsobe taken manually using pipettes and/or sampling cannula/syringeassemblies. Miniature temperature probes 355 associated with each vesselV can also be located on automated assembly 349.

[0084] In a typical operation, each vessel V is filled with apredetermined volume of media. Dosage units are dropped either manuallyor automatically into the bottoms of each media-containing vessel V, andeach paddle 343B (or other agitation or USP-type device) is rotatedwithin its vessel V at a predetermined rate and duration within the testsolution as the dosage units dissolve. In other types of tests, acylindrical basket (not shown) loaded with a dosage unit is substitutedfor each paddle 343B and rotates within the test solution. For any givenvessel V, the temperature of the test solution can be maintained at aprescribed temperature if desired (e.g., approximately 37±0.5° C. ifcertain USP dissolution methods are being conducted). Solutiontemperature is maintained by immersion of vessel V in the water bath ofwater bath container 315 (or alternatively by direct heating asdescribed previously). Accordingly, the temperature of the test solutionis dependent upon, and thus indirectly controlled by, the temperature ofthe water bath which in turn is dictated by the external heating meansemployed. Temperature probe 355 is used to monitor the test solutiontemperature, and can be any suitable type of transducer such as athermistor. Preferably, sampling manifold 349 lowers the variouscannulas and probes associated with media preparation/testing apparatus300 into corresponding vessels V only while samples are being taken atallotted times. At all other times, the cannulas and probes are keptoutside of the media contained in vessels V, thereby significantlyreducing the turbulence created by whichever cannulas and probes areused. Sample cannulas 351 and return cannulas 353 can be respectivelyconnected to sample lines SL and return lines RL to integrate mediapreparation/testing apparatus 300 with the systems described hereinaboveand illustrated in FIGS. 3, 8 and 9.

[0085] Referring back to FIG. 9, the operation of sample analysis system250 will now be described. One or more samples of media are transferredfrom selected test vessels V₁-V₆ (mounted, for example, in mediapreparation/testing apparatus 300) through media sample lines(collectively designated SL in FIG. 9) to corresponding samplemeasurement components of set F of flow cells. After opticalmeasurements are taken, the samples are returned to test vessels V₁-V₆through media return lines (collectively designated RL in FIG. 9).Calibration operations can also be carried out prior to test runs usingblank sample media vessel BV and standard sample media vessel SV asdescribed previously.

[0086] Multiplexing apparatus 10 is operated as described with referenceto FIGS. 1-7C. Preferably, the movements of multiplexing apparatus 10are coordinated with the operations of the other elements of sampleanalysis system 250 under the control of a suitable electronicprocessing device such as a computer (not shown). Accordingly, sourceline and return line selector devices 80 and 130 of multiplexingapparatus 10 are initially set to their respective home positions. Atthe home positions, one of the bundle of optical fiber source lines OSLis positioned (e.g., at “index position 1”) in optical coupling relationwith optical input bus IB, and a corresponding one of the bundle ofoptical fiber return lines ORL is positioned (e.g., at a corresponding“index position 1”) in optical coupling relation with optical output busOB. In effect, multiplexing apparatus 10 selects a sample measurementcomponent from set F of sample measurement components corresponding tothe selected index position of source and return selector devices 80 and130.

[0087] To take a measurement of the sample residing in the selectedsample measurement component, light source 210 sends a beam of light ofintensity P₀ into input bus IB. Source line selector device 80 ispositioned such that the light is routed into the selected one of thebundle of source lines OSL. This source beam (or pulse) is thustransmitted into the particular sample measurement component thatcorresponds to the selected source and return lines OSL and ORL.

[0088] Light source 210 and the sample residing in the selected samplemeasurement component can together be considered as a signal generator,in that light source 210 and the sample conjoin to generate theanalytical signal in the form of an attenuated beam of light ofintensity P as the beam of light passes through the sample. Theanalytical signal is transmitted through the selected one of returnlines ORL back to multiplexing apparatus 10 and, due to the position ofreturn line selector device 130 (see FIG. 8), is routed into output busOB. Output bus OB transmits the analytical signal to signal receivingdevice 230 for detection and processing, and the concentration of themeasured sample is determined from the value obtained from its measuredlight absorbance, using calibration curves if necessary.

[0089] Within signal receiving device 230, wavelength selector 232 istypically provided in the form of a filter or monochromator thatisolates a restricted region of the electromagnetic spectrum forsubsequent processing. Detector 234 converts the radiant energy of theanalytical signal into an electrical signal suitable for use by signalprocessor 236. Signal processor 236 can be adapted to modify thetransduced signal in a variety of ways as necessary for the operation ofsignal receiving device 230 and the conversion to a readout signal.Functions performed by signal processor 236 can include amplification(i.e., multiplication of the signal by a constant greater than unity),logarithmic amplification, ratioing, attenuation (i.e., multiplicationof the signal by a constant smaller than unity), integration,differentiation, addition, subtraction, exponential increase, conversionto AC, rectification to DC, comparison of the transduced signal with onefrom a standard source, and/or transformation of the electrical signalfrom a current to a voltage (or the converse of this operation).Finally, readout device 238 displays the transduced and processedsignal, and can be a moving-coil meter, a strip-chart recorder, adigital display unit such as a digital voltmeter or CRT terminal, aprinter, or a similarly related device.

[0090] It will be understood that the embodiments described hereinabovecan be slightly modified to utilize more than one mediapreparation/testing apparatus 300, more than signal receiving device230, and/or more than one set F of sample measurement components.

[0091] Referring back to FIG. 3, some of the features of the systemsdescribed with reference to FIGS. 8 and 9 are schematically shown inoperative communication with multiplexing apparatus 10. Light source 210optically communicates with input bus IB, and output bus OB opticallycommunicates with signal receiving device 230. Sample measurementcomponent F₁ fluidly communicates with sample line SL₁ and return lineRL₁, and optically communicates with optical source line OSL₁ andoptical return line ORL₁. As described hereinabove, optical source lineOSL₁ is connected to one of fittings 33 of source line selector device80, and optical return line ORL₁ is connected to one of fittings 35 ofreturn line selector device 130. It will be understood that other samplemeasurement components F₂-F_(n) can be analogously interfaced withmultiplexing apparatus 10 and other corresponding media sample lines andmedia return lines (not shown).

[0092] As indicated previously, remote flow cells are but one type ofmeans for encoding information that can be processed by signal receivingdevice 230. Other examples of sample measurement components arefiber-optic probes, or dip probes, that are designed for insertiondirectly into a container holding an analyte-containing media. In someapplications, the use of dip probes has been a substitute for theremoval (and preferably the subsequent return) of samples from the mediacontainer and the transfer of the samples to the sample cell of aspectroscopic or other sample analyzing apparatus.

[0093] In addition to the use of sample containment means such as flowcells, dip probes and the like as specified hereinabove, other means andaccessories can be employed for generating analytical data in accordancewith the invention. For example, instead of absorption probes,reflectance probes can be employed for undertaking reflectancemeasurements of samples. As appreciated by persons skilled in the art, atypical reflectance probe includes two fiber-optic bundles. One bundleforms a central core and delivers light to the sample. The other bundlesurrounds the central core, and collects the light reflected from thesample and returns it to the detector of the associated sample analyzinginstrument. Alternatively, a transmission probe can be employed toenable the measurement of solid samples. A typical transmission probeincludes two single optical fibers. One fiber delivers light to thesample, and the other collects the light transmitted through the sampleand returns the transmitted light to the sample analyzing instrument.The transmission probe is preferably used in conjunction with a sampleholder adapted to position the sample for measurement. The nature of thesample (e.g., textile fabrics, sunglasses) dictates the design of thesample holder. Transmittance data can also be acquired from solidsamples using an integrating sphere, which is a hollow sphere having aninternal surface that is a non-selective diffuse reflector. Integratingspheres are often used to measure the transmission of turbid,translucent, or opaque refractory materials in situations where othertechniques are inadequate due to loss of light resulting from thescattering effects of the sample.

[0094] Referring back to FIGS. 1-3, while input bus IB can be directlycoupled to light source 210 and output bus OB directly coupled to signalreceiving device 230, this is not a requirement of the invention. Theinvention contemplates that various accessories and adaptations can beemployed, such as those indicated hereinabove, and that multiplexingapparatus 10 can be integrated with existing analytical systems, inaccordance with specific applications of multiplexing apparatus 10. Forexample, in FIGS. 1-3, multiplexing apparatus 10 can additionallyinclude a fiber-optic coupling unit, generally designated 425, forrouting light beams into and out from fiber-optic cables. Fiber-opticcoupling unit 425 comprises an enclosure 431, fittings 433 and 435mounted to one or more walls of enclosure 431, one or more internaloptical mirrors 437 and 439 (see FIG. 3) disposed within enclosure 431and positioned at desired angles, one or more apertures 441 and 443 (seeFIGS. 1 and 2) formed in the walls of enclosure 431, and various typesof lenses (not shown) if needed. The input end of input bus IB isconnected to fitting 433, and the output end of output bus OB isconnected to fitting 435. As best illustrated in FIG. 3, a source signalfrom light source 210 enters enclosure 431 through aperture 441 (seeFIG. 1), is reflected off internal mirror 437, and is diverted intoinput bus IB.

[0095] A return signal from output bus OB is reflected off internalmirror 439 and diverted toward signal receiving device 230 throughaperture 443 (see FIG. 1).

[0096] Referring now to FIGS. 11, 12A, and 12B, another analyticaltesting and data acquisition system, generally designated 600, isillustrated according to another embodiment of the present invention. Insome cases, it may be desirable to eliminate either the multiplexing orthe demultiplexing feature of the invention. Accordingly, thisembodiment provides an alternative multiplexing apparatus, generallydesignated 10′, in which return line selector device 130 has beeneliminated. Source line selector device 80 functions as describedhereinabove. In the present embodiment, multiplexing apparatus 10′comprises an output bus mounting assembly 630. Output bus mountingassembly 630 includes an output aperture 632 in which a lens 634 ispreferably disposed. Lens 634 can be situated at the terminal end of acylindrical collar 636 or other suitable means for retaining andcollecting optical return lines ORL₁-ORL_(n) in a fixed-position bundle.In this embodiment, the bundle of optical return lines ORL₁-ORL_(n)collected from, for example, aperture rows 16 or 18 (see FIGS. 2 and 3)is considered in effect to be a multi-channel output bus for analyticaltesting system 600. The bundle of optical return lines ORL₁-ORL_(n)could also include an extra test line that is connected to a referencesource.

[0097] In FIG. 12A, for example, a total of nine lines are illustrated.For another example, a 16-channel system would have seventeen lines(again assuming one test line were included).

[0098] Output aperture 632 is optically aligned with the receivingwindow of a sample detector SD or other similar analyzing device orlight-receiving component thereof.

[0099] In operation, a sample beam from light source 210 is directedthrough input bus IB into the input side of source line selector device80 in the manner described hereinabove. As also described hereinabove,source line selector device 80 is indexed by motor 40, shaft 42, gearwheels 45 and 47, and other associated components (see FIGS. 2 and 3) soas to select one of optical source lines OSL₁-OSL_(n). The signal istransferred out from source line selector device 80 through the selectedoptical source line OSL₁-OSL_(n) and associated fitting of one ofaperture rows 16 and 18 to the selected sample container or other typeof test site F₁-F_(n) of encoding system 220. The transmitted light beamP is then returned through the corresponding one of optical return linesORL₁-ORL_(n), through one of aperture rows 16 or 18, to output busmounting assembly 630 where all optical return lines ORL₁-ORL_(n) arebundled at output aperture 632. Transmitted light beam P emanating fromselected optical return line ORL₁-ORL_(n) is directed into the window ofsample detector SD. This window is large enough to receive light fromany of the ends of optical return lines ORL₁-ORL_(n) bundled at outputbus mounting assembly 630.

[0100] As an example, the window can be approximately 1 cm² in area, andthe fiber ends of optical return lines ORL₁-ORL_(n) can be positionedapproximately 0.5 cm away from the window.

[0101] It will be noted that multiplexing apparatus 10′, in which eithersource line selector device 80 or return line selector device 130 iseliminated, and either including or not including the other features ofspectrophotometer 600, can be integrated into the various systems of theinvention described with reference to FIGS. 3, 8-10 in the place ofmultiplexing apparatus 10.

[0102] It is therefore seen from the foregoing description that thepresent invention provides a sample analysis system and method thatbenefit from the use of fiber-optics and optical routing and selectionmeans. The embodiments described herein result in high-quality analysisand quantification of analytical samples with decreased effort, expense,and time, and enable the efficient and controlled selection and routingof optical signals and signal paths with minimal light loss.

[0103] It will be understood that the spectrophotometers describedhereinabove are generally of the type involving the transmissionmeasurement of a sample, wherein a light beam passes through a samplecell or flow cell containing the sample to be analyzed. The invention,however, is equally applicable to spectrophotometers of the type inwhich the sample to be analyzed is subjected to reflectance measurementand consequently do not necessarily require a sample cell or flow cellfor operation.

[0104] It will be further understood that various details of theinvention may be changed without departing from the scope of theinvention. Furthermore, the foregoing description is for the purpose ofillustration only, and not for the purpose of limitation—the inventionbeing defined by the claims.

What is claimed is:
 1. A sample analysis system comprising: (a) aplurality of media containers; (b) a plurality of sample test sites; (c)a plurality of media sampling lines, each media sampling line adaptedfor transferring a quantity of media from each respective mediacontainer to each respective sample test site; (d) a plurality ofoptical source lines, each optical source line having an optical sourceline input end and an optical source line output end, each opticalsource line output end coupled to each respective sample test site; (e)a plurality of optical return lines, each optical return line having anoptical return line input end and an optical return line output end,each optical return line input end coupled to each respective sampletest site; and (f) an optical input selection device rotatable about afirst axis and comprising a first internal optical fiber having a firstinput end and a first output end, the first input end disposedcollinearly with the first axis, the first output end disposed at aradially offset distance from the first axis and alignable with aselected optical source line input end.
 2. The system according to claim1, comprising a plurality of media return lines, each media return lineadapted for transferring the quantity of media from each respectivesample test site back to each respective media container.
 3. The systemaccording to claim 1, wherein the optical input selection devicecomprises: (a) a first rotary element rotatable about the first axis,the first rotary element comprising a first input end surface and anopposing first output end surface, wherein the first input end of thefirst internal optical fiber is exposed at the first input end surfaceand the first output end of the first internal optical fiber is exposedat the first output end surface; and (b) a first stationary elementdisposed adjacent to the first output end surface and having a pluralityof circumferentially spaced first stationary element apertures, whereineach first stationary element aperture is disposed at the radiallyoffset distance from the first axis, and the first output end of thefirst internal optical fiber is alignable with a selected one of thefirst stationary element apertures through rotation of the first rotaryelement.
 4. The system according to claim 3, comprising an opticaloutput selection device rotatable about a second axis and comprising asecond internal optical fiber having a second input end and a secondoutput end, the second input end disposed at a radially offset distancefrom the second axis and alignable with a selected one of the returnline output ends, and the second output end disposed collinearly withthe second axis.
 5. The system according to claim 4, comprising arotatable coupling mechanism interconnecting the optical input selectiondevice and the optical output selection device, wherein rotation of thecoupling mechanism causes rotation of the first output end and thesecond input end.
 6. The system according to claim 1, comprising anoptical output selection device rotatable about a second axis andcomprising a second internal optical fiber having a second input end anda second output end, the second input end disposed at a radially offsetdistance from the second axis and alignable with a selected one of thereturn line output ends, and the second output end disposed collinearlywith the second axis.
 7. The system according to claim 6, comprising arotatable coupling mechanism interconnecting the optical input selectiondevice and the optical output selection device, wherein rotation of thecoupling mechanism causes rotation of the first output end and thesecond input end.
 8. The system according to claim 1, comprising a lightsource optically communicating with the first input end of the firstinternal optical fiber.
 9. The system according to claim 1, comprisingan optical receiving device, wherein each optical return line output endis selectively alignable with the optical receiving device.
 10. Thesystem according to claim 1, comprising a mounting member, wherein eachoptical return line output end is defined by an optical fiber supportedby the mounting member.
 11. The system according to claim 10, comprisingan optical receiving device, wherein each optical return line output endis optically aligned with the optical receiving device.
 12. A sampleanalysis system comprising: (a) a plurality of media containers; (b) aplurality of sample test sites; (c) a plurality of media sampling lines,each media sampling line adapted for transferring a quantity of mediafrom each respective media container to each respective sample testsite; (d) a fiber-optic channel selecting instrument comprising: (i) anoptical input selection device defining a first adjustable optical path,the first optical path running between a first input end and a firstoutput end, the first output end rotatable to a plurality of first indexpositions defined along a first circular path; (ii) an optical outputselection device defining a second adjustable optical path, the secondoptical path running between a second input end and a second output end,the second input end rotatable to a plurality of second index positionsdefined along a second circular path; and (iii) a controller elementcommunicating with the optical input selection device and the opticaloutput selection device for selectively aligning the first optical pathwith the first index positions and the second optical path with thesecond index positions; (e) a plurality of optical source linescorresponding to the plurality of first index positions and selectivelycommunicating with the first optical path, each optical source linecommunicating with each respective sample test site; and (f) a pluralityof optical return lines corresponding to the plurality of second indexpositions and selectively communicating with the second optical path,each optical return line communicating with each respective sample testsite.
 13. The system according to claim 12, wherein the optical inputselection device comprises: (a) a first rotary element rotatable about afirst axis, the first rotary element comprising a first input endsurface and an opposing first output end surface, wherein the firstinput end of the first optical path is exposed at the first input endsurface and the first output end of the first optical path is exposed atthe first output end surface; and (b) a first stationary elementdisposed adjacent to the first output end surface and having a pluralityof circumferentially spaced first stationary element apertures, whereineach first stationary element aperture is disposed at the radiallyoffset distance from the first axis, and the first output end of thefirst optical path is alignable with a selected one of the firststationary element apertures through rotation of the first rotaryelement.
 14. The system according to claim 13, wherein the opticaloutput selection device comprises: (a) a second rotary element rotatableabout a second axis, the second rotary element comprising a second inputend surface and an opposing second output end surface, wherein thesecond input end of the second optical path is exposed at the secondinput end surface and the second output end of the second optical pathis exposed at the second output end surface; and (b) a second stationaryelement disposed adjacent to the second input end surface and having aplurality of circumferentially spaced second stationary elementapertures, wherein each second stationary element aperture is disposedat the radially offset distance from the second axis, and the secondinput end of the second optical path is alignable with a selected one ofthe second stationary element apertures through rotation of the secondrotary element.
 15. The system according to claim 12, wherein thecontroller element comprises a rotatable coupling mechanisminterconnecting the optical input selection device and the opticaloutput selection device, wherein rotation of the coupling mechanismcauses synchronized rotation of the first output end of the firstoptical path and the second input end of the second optical path.
 16. Asample analysis system comprising: (a) a plurality of media containers;(b) a plurality of sample test sites; (c) a plurality of media samplinglines, each media sampling line adapted for transferring a quantity ofmedia from each respective media container to each respective sampletest site; (d) a fiber-optic channel selecting instrument comprising arotary element rotatable about a central axis, and an internal opticalfiber having an internal optical fiber input end and an internal opticalfiber output end, the internal optical fiber input end disposedcollinearly with the central axis, and the internal optical fiber outputend disposed at a radially offset distance from the central axis; (e) aplurality of optical source lines having respective source line inputends, each source line input end selectively optically alignable withthe internal optical fiber output end; (f) a plurality of optical returnlines terminating at respective optical fiber ends; and (g) a mountingmember supporting the optical fiber ends.
 17. The apparatus according toclaim 16, wherein: (a) the rotary element comprises an input end surfaceand an opposing output end surface, the internal optical fiber input endis exposed at the input end surface and the internal optical fiber output end is exposed at the out put end surface; and (b) the fiber-opticchannel selecting instrument comprises a stationary element disposedadjacent to the output end surface and having a plurality ofcircumferentially spaced stationary element apertures, each stationaryelement aperture is disposed at the radially offset distance from thecentral axis, and the internal optical fiber output end is alignablewith a selected one of the stationary element apertures through rotationof the rotary element.
 18. The system according to claim 16, comprisinga light source optically communicating with the internal optical fiberinput end.
 19. The system according to claim 16, comprising an opticalreceiving device disposed in alignment with the optical fiber ends ofthe optical return lines.
 20. A method for acquiring data from samples,comprising the steps of: (a) providing a plurality of samplesrespectively disposed in a plurality of media containers; (b) providinga plurality of test sites; (c) providing a plurality of optical sourcelines, wherein each source line communicates with each respective testsite; (d) providing a plurality of optical return lines, wherein eachreturn line communicates with each respective test site; (e) providing aplurality of media sampling lines, wherein each media sampling linefluidly interconnects a respective media container with a respectivetest site; (f) selecting a test site and the source line, return lineand media container corresponding to the selected test site by rotatinga fiber-optic channel selecting apparatus to a position at which theselected source line communicates with a light source; (g) transferringthe sample disposed in the selected media container through itscorresponding media sampling line to the selected test site; and (h)sending an optical signal of a first intensity through the selectedsource line to the selected test site to expose the sample transferredto the selected test site, whereby an optical signal of a secondintensity is emitted from the selected test site and travels through theselected return line.
 21. The method according to claim 20, comprisingthe steps of: (a) selecting a next one of the test sites and the sourceline, return line and media container corresponding to the next testsite by rotating the fiber-optic channel selecting apparatus to a nextposition at which the next source line communicates with the lightsource; (b) transferring a next one of the samples disposed in the nextmedia container through its corresponding media sampling line to thenext test site; and (c) sending an optical signal of a first intensitythrough the next source line to the next test site to expose the sampletransferred to the next test site, whereby an optical signal of a secondintensity is emitted from the next test site and travels through thenext return line.
 22. The method according to claim 20, wherein rotationof the fiber-optic channel selecting apparatus brings the selectedreturn line into communication with an optical receiving device.
 23. Themethod according to claim 20, comprising the step of positioning allrespective terminal ends of the return lines in alignment with anoptical receiving device.